He said five teachers including one woman were also poisoned and were under treatment.

“The patients are suffering from delirium, laugh, crying, tearing and eye redness,” he said, adding that six members of a family were also brought in to a clinic in a separate similar incident.

Provincial police chief Sakhi Dad Haidari said the chemical materials in the laboratory of the school have caused the illnesses.

But public health director said the cause of the incident was not clear so far. He added that a delegation including two specialists have been appointed to visit the patients and get their blood sample to identify reason behind the incident.